The amount of radiation from the atmosphere to the surface as the main input on the use of solar power in the design and modeling of the relevant equipment. As well as other phenomena in nature, such as the intensity of solar radiation on the surface evaporates, flooding, rain, environmental pollution and also has a direct effect. Because of this, many models have been developed to measure a parameter that varies proportional to the geography and climate of each region with each other. In this study, using data  between 1957 and 2005 in the city of Bam measured in Kerman province, the amount of solar radiation received by Earth-based models such as AngstroÈm and Paige were calibrated. It was extended to Bam relations and curve light intensity for each of the actual radiation that have been extracted from the Meteorological Organization of Iran, was drawn. Then the measured value of the model were compared with the computational model most consistent with the values recorded for the station in question, was selected as the optimal model for the Bam area. Evaluation of the relationship and estimate the error of each of them, with conventional tests and the use of quantities such as the average percentage error, mean baseline error, root mean square error, the standard error of the estimate and the correlation coefficient were used. Thus, all comparative figures in the tables are calculated on the basis of their classification and optimal model was chosen for the city of Bam. As a result of the proposed relations for the city of Bam, the possibility of modeling to estimate the intensity of the sun at any time of the year will be possible.